I have a Samsung cell phone and am having the same problem with the phone continually ringing. It worked great for 3 months, then all the sudden, the incoming call will not disconnect, even when the caller hangs up.
I callled support and they said it was a software issue with my provider and I should take my phone in for a software upgrade, which I did. This did not correct the problem and the phone service provider, Verizon said it is a Pioneer problem.